1. Field of the Invention
The present invention relates to a mobile communication system based on a GSM (Global System for Mobile Communication) method and particularly to an RLP frame receiving method capable of transmitting an RLP (Radio Link Protocol) frame promptly and accurately.
2. Background of the Related Art
A mobile communication system allows a user to communicate with someone through radio paging and a wireless connection any time and anywhere while moving in a service area. With the development of mobile communication—related techniques, mobile communication systems can perform data communication as well as a communication using a voice grade signal. Currently, there exist mobile communication systems, using a GSM (Global System for Mobile Communication) method, which is a kind of TDMA (Time Division Multiple Access) method.
It is quite probable that mobile communication systems generate data errors due to influences of various radio environments, since the system transmits/receives data wirelessly. In order to reduce the probability of data error generation caused by radio environment characteristics, an RLP (Radio Link Protocol) has been developed.
When an error is generated in data transmitted in a frame unit, the RLP requests retransmission of the error—generated frame, in accordance with a retransmission protocol of wireless data on the basis of a NAK (Negative Acknowledge) method. Thus, the RLP can correctly transmit data wirelessly without errors.
However, a presently used transmission method of wireless data is operated uniformly without consideration of various radio environment characteristics in a radio section. Accordingly, the mobile communication system needs a method for receiving data more effectively and quickly by improving the retransmission method of the radio data.
Also, in the receiving method of an RLP frame in accordance with the conventional art, the RLP frame corresponding to an generated error frame is repeatedly transmitted by using the NAK method, so that an accurate data transmission and reception may be possible, but the method does not consider various radio environments. Accordingly, since the RLP frame corresponding to the error frame is repeatedly requested and received for a predetermined number of times in a relatively bad radio environment, an entire data transmission rate is lowered and a load in the mobile communication system is increased.